Today the Zipp 303 SW launches with an updated design and an AXS connection for an integrated pressure sensor. This replaces the much loved Zipp 303 Firecrest and does it with a new focus on all-road use, more strength, and of course that pressure sensor.
In many ways this is an expansion of something that started last year with the 303 XPLR SW you’ll find in our component reviews. That release allowed Zipp to have an actual gravel wheel at two price points. With that extra space, Zipp is offering something unexpected that attempts to bridge the gap.
I’ve had a brief chance to explore the claims and spend some time on these wheels and now I’m ready to share. I’ll spoil it by saying I think you’ll want to readjust your use case but as long as that happens, the Zipp 303 SW are worth a look. Let’s talk about what I mean.
Quick hits: 7 standout details of the Zipp 303 SW wheelset
- The Firecrest was often considered a second tier gravel wheel while the 303 SW is being marketed as an all-road wheel
- As seen in Enve wheels, there’s now a hefty lip along the tire to help prevent pinch flats
- The ZR1 hub is a j-spoke design that gets an update of the bearings for better reliability
- Wheelset weight is quoted at 1440 grams
- You’ll need to carry tubes with a threaded valve stem making options limited
- A quick glance at a flashing light is all you need to know if you are ready to ride
- AXS connection provides real time pressure data to headunits and phones
- Uses a 2032 coin cell battery with no charging required.
- For more info and purchase visit the Zipp website.
Quick takeaway: Requiring a specific sealant injector and tubes with threaded valve stems is a bit of a hassle but solvable. Ultimately the Zipp 303 SW wheelset is a solid second tier road wheelset. It might be possible to run these on gravel but they don’t feel ideal for that scenario and a 303 XPLR wheel does better even for mixed use scenarios. Just take these as a slightly heavier, less expensive, road option (compared to the 353 NSW) and the integrated pressure sensor definitely makes life a bit easier.
details | ride experience | conclusion
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Zipp 303 SW details
This section actually deserves a little bit of history. The conceptual use case for these wheels is a big part of both what I’m leaning on in the review and also what Zipp marketing is leaning on.
As far as the actual wheel part of this launch, the Zipp 303 SW is a replacement for the 303 Firecrest but it’s not an exact replica with a sensor added.
In terms of specs, both wheels are 40mm deep and 25mm wide internally. They also look roughly the same but the new wheel is 33mm wide up from 30mm on the old wheel and there’s quite a step at the edge of the wheel next to the tire. The step protects the tire during an impact.
Going beyond the dimensions you’ll also find some material differences. The new wheel is 10% stronger and the updated ZR1 hub shifts to stainless steel bearings for “improved durability and smoother performance.” The scale will also show an increase of quoted weight from 1408 grams to 1440 because of a combination of the new dimensions and the integrated sensor.
Aside from all that, this wheel is now being marketed as an all-road wheel. That distinction is important because previously the Firecrest wheel was used as often as a price focused gravel wheel as it was as a road wheel. Now there’s an option for two different gravel wheels and you can expect the 303 SW to slot in as a modern road bike wheel that handles whatever modern road cycling might cover.
It’s also worth noting that the top-shelf road wheel in the Zipp lineup is the 353 NSW, which is also getting an update today, and Zipp says that wheel should not be ridden off-road.
That market positioning backstory helps me, and you, fairly judge what this wheel should do. It should also help you understand when you might want to consider this wheel. There’s a bit more info I learned during my riding it but first, there’s one more trick.
The feature that really sets these wheels apart is the new integrated AXS pressure sensor. The way that piece works is that there’s a cartridge that slides into a space molded into the carbon of the wheel. It slides over the valve stem and weighs 12-grams including the 2032 battery that powers it. Externally all you see is a seam on the inside of the wheel plus a light and the AXS logo.
That light is the heart of how it works in use. You start by using your AXS app to set your desired pressure. SRAM would certainly hope that you use the SRAM tire pressure guide but you don’t have to. Once that’s set you walk up to the bike and bounce it and the sensor will wake up then flash green if it’s within range, slow red if it’s low, or a double flash red if it’s high.
While riding you can also see the pressure or you can check the exact numbers at any time. If you want to watch pressure constantly while riding then add the sensor to your Wahoo, Hammerhead, or Garmin bike computer and you can add a data field for real time pressure on the screen. Alternatively you can always open the AXS app and it will show the pressure from both sensors.
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Ride experience
The way I’ve experienced these wheels so far is, as paired by Zipp, with Zipp/Goodyear Z30 SW tires. Oddly they caliper out to 29mm when installed and aired up. There is also a 35mm width available and you can use other tires as you see fit but you’ll want to check compatibility with hookless tubeless applications.
This detail is important since tires will, obviously, impact how a wheel feels. This is the vision of Zipp designers though. You can think of this combo as the chef’s choice and that’s how I’ve tested.
I say all that because what I found was that I would not consider this combo ideal for all-road use. The wheels feel stiff even on a rather compliant Trek Madone. You can see me run through different scenarios in the video above but the takeaway is that I like the feel on the road.
I typically ride a 28mm tire so moving to 29mm (calipered width) and using these as an everyday wheel, that’s unlikely to break because of rough pavement, felt perfect. The 1440 gram weight is never an issue and I found myself grateful for the 40mm height in a few gusty wind situations. I’d call myself surprised at the perceived aero feeling in flat and fast situations and the climbing was exactly what you’d expect for the weight. With plenty of lateral stiffness to handle any sprinting I’m capable of I found these to feel quite responsive as well. I especially enjoyed uphill sprints through twisty roads as the lateral performance is a highlight.
Mostly though, these are the kind of wheels that disappear under you in the best way possible. As long as I stop thinking of these as a wheel I might want to take off road, I would recommend them all day long. Perhaps more importantly, if you are shopping for a road bike that has the Zipp 303 SW included then consider it a good thing. I would mentally take a wheel upgrade off the list of things to change for any bike that includes them.
The place where things get a little messy is on gravel. A good comparison to these would be the Reserve 40|44. I recently tested those wheels on a gravel bike with 44mm tires and they felt great. My guess is that even if you moved to a wider tire the Zipp 303 SW is a stiffer wheel than the Reserve. If your focus is really on gravel riding, or even heavy mixed surfaces, I’d choose differently. Except there’s an integrated tire pressure sensor.
The catch on these wheels is that sensor. You can see, again a reference to the video, that not everyone is going to be on board with the idea of more electronics on a bike. If that’s you, I probably can’t say much but I will say that I loved having it.
In most cases I walk out to the bike I plan to ride on a particular day and I add pressure automatically. There’s no easy way to check pressure without attaching a pump so I attach the pump and add a bit of pressure. It’s likely that’s often unnecessary and I’m adding pressure based on what’s lost attaching the pump.
With the Zipp 303 SW I walk out to the bike and I look at the light. A good portion of the time it’s blinking green and I’m ready to go. If it’s low I’ve been adding pressure with the Silca Electtrico electric pump and the claimed 1% accuracy of that gauge has been aligning perfectly with the reported pressure.
There’s also two places I haven’t tested this setup yet but it would be ideal. Actually I’ve tested this with the previous standalone TyreWiz which is exactly the same. Either way though, if you experience a flat while riding you would now have a way to know your exact pressure after repairing the tire. The other scenario that the system would be ideal for is changing pressure going on and off of gravel during a ride.
I did spend some time using a Hammerhead Karoo with the pressure sensor displayed on screen. There’s no reason to use this if you ride with a phone and I promptly removed it. If I experience a flat, I’ll know and would stop to check pressure and add more as necessary. If I am changing pressure purposefully then I will also know it’s happening. In both situations I can look at the AXS app to check the numbers.
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Conclusion
The Zipp 303 XPLR is an incredible wheel. It works almost as well on the road as it does off-road and Zipp is now offering a road tire to fit those wheels. If you have a gravel bike that you want to use on and off-road I’d recommend those wheels instead.
Where the Zipp 303 SW makes sense is as a modern all around road wheel. It’s fast on the flats and when climbing. The stiffness I’m less enamored with off-road feels great under acceleration and during quick directional changes. If you take it off road anyway, it’s unlikely to have an issue and if it does then “the 303 SW wheel is covered by Zipp’s Lifetime Warranty, covering you not just for any manufacturing defects, but also for any system failure that occurs while riding your bike within the intended use of your Zipp wheel. If your 303 SW wheel fails while riding, we will repair or replace it free of charge. Zipp’s Lifetime Warranty covers all structural damage that occurs to the rim while riding, including damage from a crash or rim impact.”
The integrated pressure sensor is a bonus on top of that performance. I love being able to instantly see if the bike is ready to ride. I also love the idea of knowing with certainty that I’ve reinflated a tire after a flat. Those two things are incredibly useful.
The downsides are that the pressure sensor makes things a little more fiddly. There’s added weight both for the sensor and for balancing the sensor weight but I don’t think that’s important. I do think it’s a hassle to need a specific type of tube in case of an emergency and I also think it’s a hassle to need a specific sealant injector. You can overcome both issues but it’s worth thought and careful planning.
Bottom line, grab the Zipp 303 SW if you like the convenience of the sensor and excellent warranty at a reasonable price point for a workhouse do everything carbon wheelset. If these come on a bike, gravel or road, stock up on tubes and otherwise forget about them.